Langley Waterproofing Limited

Paratech 40 Hot-Melt Roofing Systems

Manufacturer: Langley Waterproofing Limited 

Materials: Hot Applied Polymer Modified Bitumen (Hot Melt) 

Paratech 40 Hot-Melt Roofing Systems consist of a hot-applied modified bitumen reinforced with interwoven glassfibre, and are used in conjunction with a range of modified bitumen roofing membranes.
1.2 The systems comprise:
• Langley Paratech HM — a polymer-modified bitumen hot-applied liquid membrane
• Langley Hi-Pen HM Primer — a cold-applied synthetic rubber based primer for use on all concrete and masonry substrates
• Paratech R Reinforcing Fabric — a resin-coated interwoven glassfibre reinforcement
• Langley Bitumen Primer — a black, quick-drying bitumen priming solution, consisting of bitumens and hydrocarbon solvents, for use on concrete surfaces
• the subject of BBA Certificate 10/4807 Paradiene 35 SR4 HM — a polyester-fibre (180 g·m–2) reinforced, polymermodified bitumen sheet with a thermofusible film or sand on both surfaces, for use as a base sheet or capsheet with additional protection
• the subject of BBA Certificate 10/4762 Graviflex HM — a polyester-reinforced, styrene-butadiene-styrene (SBS) modified bitumen membrane with a mineral or sand finish on the upper surface, for use as an anti-root layer in green roof applications and used instead of Paradiene 35 SR4 HM on green roofs
• Néodyl Strip and Néodyl Cord — an SBS modified bitumen strip and a synthetic rubber cord, for use at changes of direction, structural joints and expansion joints, and covered with mineral layer
• Langley Protection Board — a bitumen-impregnated, water-resistant cellulose board for use on sites where covering of the waterproofing is delayed and excessive foot traffic is anticipated

BBA logo

Number: 15/5276
Issue date: 29/03/2019

Approved for use on

Flat Roofs Green Roofs Inverted Roofs Podium Decks Protected Roofs Roof Gardens 

For use as a waterproofing layer on flat, including zero fall, roofs with limited access in:

• inverted roof specifications
• protected roof specifications (including podium deck roofs), eg covered by pavers or other suitable protection
• roof gardens or green roof systems


Concrete Timber 

The systems have been assessed for use on the following substrates:

• in-situ structural concrete
• precast concrete
• concrete block in vertical applications
• lightweight structural concrete (subject to the manufacturer’s recommendations)
• new exterior grade plywood (to BS EN 636 : 2012, Clause 8), fixed in accordance with the relevant requirements of BS 6229 : 2018 and BS 8217 : 2005.


Design Life of the Roof 

When fully protected and subject to normal service conditions, the systems can provide an effective barrier to the transmission of liquid water and water vapour for the service life of the roof in which they are incorporated.

Installation Requirements

The systems should only be installed by trained contractors using specialist equipment.

Fire Safety

In the opinion of the BBA, a roof incorporating the systems will be unrestricted under the national Building Regulations in the following circumstances:
• a roof garden covered with a drainage layer of gravel 100 mm thick and a soil layer of 300 mm
• when protected by an inorganic covering (eg gravel or paving slabs) listed in the Annex of Commission Decision 2000/553/EC.

In the opinion of the BBA, when used in irrigated roof gardens or green roofs, the membranes will also be unrestricted.

Exposed areas of the capsheet, when used with one of the surface finishes detailed in Approved Document B, Appendix A, Table A5, part iii (England and Wales) and Technical Booklet E, Table 4.6, part iv (Northern Ireland) (listed below), would be deemed to be unrestricted:
• bitumen-bedded stone chippings covering the whole surface to a depth of not less than 12.5 mm
• bitumen-bedded tiles of non-combustible materials
• sand and cement screed
• macadam.

The designation of exposed areas of the capsheet installed to other specifications should be confirmed by: England and Wales — test or assessment in accordance with Approved Document B, Appendix A, Clause 1, Scotland — test to conform to Mandatory Standard 2.8, clause 2.8.1, Northern Ireland — test or assessment by a UKAS-accredited laboratory, or an independent consultant with appropriate experience.

If allowed to dry, plants used in a roof garden may allow flame spread across the roof. This should be taken into consideration when selecting the plants for the roof. Appropriate planting irrigation and/or protection must be applied to ensure that the overall fire-rating of the roof is not compromised.

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Langley Waterproofing Limited

Lamport Drive
NN11 8YH

T : 01327 704778

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